function out = bandstop(x, fs, low, high, order)

if nargin == 4
    N = 4;
else
    N = order;
end

wn = [(2*low)/fs (2*high)/fs];
[B, A] = butter(N, wn,'stop');

for i = 1:size(x,2)
    out(:,i) = filtfilt(B,A,x(:,i));
end
